Mass treatment to eliminate tuberculosis from an island population.

Abstract

The global target of tuberculosis (TB) elimination by 2050 requires new approaches. Active case finding plus mass prophylactic treatment has been disappointing. We consider mass full anti-tuberculosis treatment as an approach to TB elimination in Kiribati, a Pacific Island nation, with a persistent epidemic of high TB incidence. To construct a mathematical model to predict whether mass treatment with a full course of anti-tuberculosis drugs might eliminate TB from the defined population of the Republic of Kiribati. We constructed a seven-state compartmental model of the life cycle of Mycobacterium tuberculosis in which active TB disease arises from the progression of infection, reinfection, reactivation and relapse, while distinguishing infectious from non-infectious disease. We evaluated the effects of 5-yearly mass treatment using a range of parameter values to generate outcomes in uncertainty analysis. Assuming population-wide treatment effectiveness for latent tuberculous infection and active TB of ⩾90%, annual TB incidence is expected to fall sharply at each 5-yearly round of treatment, approaching elimination in two decades. The model showed that the incidence rate is sensitive to the relapse rate after successful treatment of TB. Mass treatment may help to eliminate TB, at least for discrete or geographically isolated populations.